1.\"- 2.\" SPDX-License-Identifier: BSD-2-Clause 3.\" 4.\" Copyright (c) 2018 Kyle Evans <kevans@FreeBSD.org> 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25.\" SUCH DAMAGE. 26.\" 27.Dd June 18, 2021 28.Dt EFIDEV 4 29.Os 30.Sh NAME 31.Nm efidev , 32.Nm efirtc 33.Nd user-mode access to UEFI runtime services 34.Sh SYNOPSIS 35To compile this driver into the kernel, place the following lines in your 36kernel configuration file: 37.Bd -ragged -offset -indent 38.Cd "options EFIRT" 39.Ed 40.Pp 41Alternatively, to load the driver as a module at boot time, place the following 42line in 43.Xr loader.conf 5 : 44.Bd -literal -offset indent 45efirt_load="YES" 46.Ed 47.Pp 48The driver may be disabled by setting the 49.Xr loader 8 50tunable 51.Va efi.rt.disabled 52to 53.Dq Li 1 . 54.Sh DESCRIPTION 55The 56.Nm 57device provides user-mode access to UEFI runtime services. 58.Nm 59also includes a driver to provide a time-of-day clock using the UEFI 60real time clock (RTC). 61However, the RTC may not always be available, based on the UEFI firmware. 62If the RTC is not available, it will not be registered as a time-of-day clock 63and the time related ioctls below will not be functional. 64.Pp 65.Nm 66provides the following ioctls defined in 67.In sys/efiio.h 68with supplemental structures and constants defined in 69.In sys/efi.h : 70.Bl -tag -width indent 71.It Dv EFIIOC_GET_TABLE Pq Vt "struct efi_get_table_ioc" 72Copy the UEFI table specified by the 73.Va uuid 74field of the 75.Vt struct efi_get_table_ioc 76into the 77.Va buf 78field. 79The memory size for the buf field can be queried by passing 80.Dv NULL 81pointer as a buf value. 82The required size will be stored in the 83.Va table_len 84field. 85The size of the allocated memory must be specified in the 86.Va buf_len 87field. 88.Bd -literal -offset indent 89struct efi_get_table_ioc { 90 void *buf; 91 struct uuid uuid; 92 size_t table_len; 93 size_t buf_len; 94}; 95.Ed 96.It Dv EFIIOC_GET_TIME Pq Vt "struct efi_tm" 97Get the time from the RTC, if the RTC is available. 98The 99.Vt struct efi_tm 100passed is populated with the current time, unless an error occurs. 101.Bd -literal -offset indent 102struct efi_tm { 103 uint16_t tm_year; 104 uint8_t tm_mon 105 uint8_t tm_mday 106 uint8_t tm_hour; 107 uint8_t tm_min; 108 uint8_t tm_sec; 109 uint8_t __pad1; 110 uint32_t tm_nsec; 111 int16_t tm_tz; 112 uint8_t tm_dst; 113 uint8_t __pad2; 114}; 115.Ed 116.It Dv EFIIOC_SET_TIME Pq Vt "struct efi_tm" 117Sets the time stored by the RTC, if the RTC is available. 118.It Dv EFIIOC_VAR_GET Pq Vt "struct efi_var_ioc" 119Gets data from the variable described by the vendor and name fields of the 120.Vt struct efi_var_ioc 121into the 122.Fa data 123field. 124.Dv EFIIOC_VAR_GET Pq Vt "struct efi_var_ioc" 125will also populate the 126.Fa attrib 127field. 128.Bd -literal 129struct efi_var_ioc { 130 efi_char *name; 131 size_t namesize; 132 struct uuid vendor; 133 uint32_t attrib; 134 void *data; 135 size_t datasize; 136}; 137.Ed 138.It Dv EFIIOC_VAR_NEXT Pq Vt "struct efi_var_ioc" 139Used for enumerating all UEFI variables. 140The initial call should use an empty string for the name attribute. 141Subsequent calls should supply the vendor uuid and name of the last variable 142returned. 143.It Dv EFIIOC_VAR_SET Pq Vt "struct efi_var_ioc" 144Sets data and attributes for the variable described by the name and vendor in 145the 146.Vt struct efi_var_ioc . 147.El 148.Sh FILES 149.Bl -tag -width /dev/efi 150.It Pa /dev/efi 151.El 152.Sh SEE ALSO 153.Xr efivar 3 , 154.Xr efirt 9 155.Sh HISTORY 156A 157.Nm 158device first appeared in 159.Fx 11.1 . 160.Sh BUGS 161.Nm 162is currently only available on amd64 and arm64. 163